The archivists at Solent Sky have just located some preliminary sketches and calculations from 1944 that appear to be early thoughts for Clifton's Technical Note 4040. Of course this was never a project or even truly a concept, just a note to show that it was theoretically possible to acheive vertical flight with a RR Griffon. Images on their Facebook page.https://www.facebook.com/search/top/?q=solent%20sky%20museum